Bronco Forum - Full Size Ford Bronco Forum banner

1 - 20 of 20 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter #1
Hey Bronco Guys,

Just got an '87 Full Size XLT w/ 351 W...

2 days ago, I was on the highway w/ cruise control at 80 mph, and all was well until the RPM went nuts up to about 4500, and I turned off the cruise cntrl. From then on, the RPM is acting squirrelly. ie....from a standing start as you accellerate through 25-30 mph the engine doesn't seem to want to upshift (correct word?)...the RPM used to go up to around 3500 or so until you got to that MPH and then shift down to 2000 or so. I now have to jockey the accellerator to get the RPM back to normal, but that doesn't often work.

I've checked for trans. fluid leaks but can't find any, and keep checking the fluid (added about 2 qts in attempt to cure) and think it's OK.

What gives? Any ideas from the experienced veterans?

Bill
 

·
FSB's Bastard Child
Joined
·
2,047 Posts
It could have been a coincidence, Maybe it just got hot and was being tempermental. Happens more then you would think. Anyway...

Adding fluid if none leaked out may not have been the best idea. An overfilled tranny provides less protection. Drain it, Drop the pan, Raplce the fliter. Check for metal...Check the old fluid, Is it Bubbled? Burned? Either way, Replace it...Go from there.
 

·
Registered
Joined
·
10 Posts
Discussion Starter #3
did see a couple of tiny air bubbles on dipstick...is this normal?

How much fluid does the thing hold? Haynes manual doesn't say.:stupid

p.s. Will a fluid problem give me symptoms as I originally posted?
 

·
Registered
Joined
·
48 Posts
Is it a C6? If so, check to see that the vaccuum line running down to the tranny didn't get broken or disconnected. Also check to make sure that the vaccuum modulator thingy that screws into the tranny that the line hooks to didn't go bad.

Both of those situations will cause symptoms much like you are describing. AMHIK.



Forgive my 1st post not being an intro, group, I'll hit that board later.


Walt Breymier

1984 XLT - 351W, C6, Open Diffs, No lift, 32x11.50, lotsa rust, special 3-tone paint (Gray, Black and Primer)
 

·
Registered
Joined
·
10 Posts
Discussion Starter #6
New enough to Broncos to not know if it is a C6....how do I check?

Do I have electrical connections that might havecome loose?

Going out right now to check hoses....
 

·
Registered
Joined
·
48 Posts
This is what a C6 pan looks like:




The vaccuum line comes down from (I think) the manifold, along the transmission tunnel, and hooks into the modulator directly on the tranny on the passenger side. At some point the line changes from rubber to a metal line, then back. Mine had broken right at the point where it hooked to the mod. Cut off the broke part, pushed it on, free fix.


EDIT: To answer the electric lines question, to the best of my knowledge, not on the C6. I guess you might if it's not, but my experience ends there. :D

Walt Breymier
 

·
Registered
Joined
·
10 Posts
Discussion Starter #8
Good advice...found pan, found vacuum line, line is producing pressure, went and bought a new modulator, put it in (and put back in all the ATF that ran out on me!)...end result - No Difference while driving. #&%$%#$#

Friend brought over a Vacuum tester - at idle it measures about 14" Hg....

Any thoughts...
 

·
CheeseBurger Milkshake!!
Joined
·
3,760 Posts
Is the kickdown linkage stuck, or binding?

If not, the problem might be in the valve body.
 

·
Premium Member
Joined
·
2,183 Posts
Valve body is under the tranny pan, under the filter. You may have lost a tranny clutch or two which will cause it to slip at speed. Check your filter and pan for chips, chucks of clutch material. Haynes has a real good trouble shooting and rebuild manual for Ford trannys. It's "Barney proof".
 

·
Registered
Joined
·
10 Posts
Discussion Starter #12
Sounds like a possibility....is this something a rookie mechanic should try, or should i take it to the pro's?

How much are new clutches, and how hard to change?
 

·
Registered
Joined
·
748 Posts
mad dog said:
New enough to Broncos to not know if it is a C6....how do I check?

Do I have electrical connections that might havecome loose?

Going out right now to check hoses....

'87 with a 351W...yeah it's going to be a C6. The E4OD didn't begin it's spectacular legacy until late '89. If something is majorly wrong with the transmission, finding a 4x4 C6 isn't all that hard and won't be that expensive either. Another question I raise is about your comment "I just got it...." do you know how long the truck was sitting before you got it. If it was sitting for a while before you bought then it may act a bit funky when you drive especially up to 80MPH. I know when I first got my '86 (351W/C6) it had been sitting a while and the steering, brakes, and tranny acted a bit funny. After a couple days of driving and fluid circulation the truck was driving damn near as good as my '94, however, this may only be specific to my problem if your truck wasn't left sitting for long.
 

·
Registered
Joined
·
10 Posts
Discussion Starter #14
Good point...and in fact it had been sitting a long time. I've driven it about 800 miles now. Was hoping all the bugs would have been worked out by now, but maybe unearthing a major problem...

You mentioned the C6 not being hard to find or expensive....what am I looking at pricewise, and where do i look?
 

·
Premium Member
Joined
·
2,183 Posts
That depends on you and if you feel comfortable doing it. I rebuilt my tranny using this book and I now have 30,000 miles on it without a problem. Tranny rebuild kits can run from $40.00 - $100.00. Just depends on who you buy it from and who makes the rebuild kit. B&M makes a real good kit with good instructions. I also up graded the torque convertor to a heavy duty one and installed a B&M shift kit (valve body kit, not the steel gasket kit) at the same time. Whole thing ran me about $350.00 to rebuild my tranny.
 

·
Premium Member
Joined
·
2,183 Posts
Summit Racing or PAW have all the parts you need to rebuild your tranny. If truck sat for a while, you my have an internal seal the dryed out and took a crap.
 

·
Registered
Joined
·
748 Posts
mad dog said:
Good point...and in fact it had been sitting a long time. I've driven it about 800 miles now. Was hoping all the bugs would have been worked out by now, but maybe unearthing a major problem...

You mentioned the C6 not being hard to find or expensive....what am I looking at pricewise, and where do i look?
Well, I would say definitely less than $1K, E4ODs are above and beyond that range most of the time. You can check the net, newspapers, Ford classifieds, or even here on FSB. I've seen 4x4 C6s go for as low as $150...this was from a guy who was parting out his Ford truck, to say what kind of condition it was in exactly I dunno but it was said to operate fine before being pulled.
 
1 - 20 of 20 Posts
Top